New Gel May Regenerate Injured Nerve Fibers

The gel is injected as a liquid into the spinal cord and self-assembles into a scaffold that supports the new nerve fibers as they grow up and down the spinal cord, penetrating the site of the injury. When the gel was injected into mice with a spinal cord injury, after six weeks the animals had a greatly enhanced ability to use their hind legs and walk.

John Kessler, M.D., Davee Professor of Stem Cell Biology at Northwestern University's Feinberg School of Medicine stressed caution, however, in interpreting the results. "It's important to understand that something that works in mice will not necessarily work in human beings. At this point in time we have no information about whether this would work in human beings."

The nano-engineered gel works in several ways to support the regeneration of spinal cord nerve fibers. In addition to reducing the formation of scar tissue, it also instructs the stem cells, which would normally form scar tissue, to instead to produce a helpful new cell that makes myelin. Myelin is a substance that sheaths the axons of the spinal cord to permit the rapid transmission of nerve impulses.

The gel's scaffolding also supports the growth of the axons in two critical directions - up the spinal cord to the brain (the sensory axons) and down to the legs (the motor axons.) "Not everybody realizes you have to grow the fibers up the spinal cord so you can feel where the floor is. If you can't feel where the floor is with your feet, you can't walk," Kessler said.

Now Northwestern researchers are working on developing the nano-engineered gel to be acceptable as a pharmaceutical for the Food & Drug Administration.